This research aimed to investigate the current trends of rooftop greening techniques of frequent use within and without Korea. It is also expected that this research will help developing new rooftop greening techniques appropriate for Korean environment. Data for this study have been collected from patent applications for rooftop greening techniques; the web sites of the Korean Intellectual Property Office as well as patent offices in Germany and Japan, where active researches on rooftop greening techniques are in progress. 168 applications within a period from the year of 1984 to December of 2004 were examined, among which Japan excelled with its 81 applications followed by Germany(54), Korea(31)and USA(2). In case of Japan, where more patent applications were found than in any other countries, applications for Plant Base(38) excelled others - System(36), Management(4) and Plant(3) in the number of applications. As for Germany, 25 cases were on Plant Base, 25 cases on System, and 4 cases on Plant; in Korea, 15 cases were on Plant Base, 11 cases on System, 3 cases on Plant and 2 cases on Management; in USA, 1 cases were on System and 1 cases on Plant. Overall, the total number of patent applications in three countries reaches 168 cases; among which Plant Base topped in all four countries, followed by 73 cases on System. Applications concerning Plant and Management totalled to 11 and 6 for each. In conclusion, most patents were concentrated on Plant Base and System while researches on Plant and Management still do not get as much attention as they deserve. Research and development of various techniques on Plant must be a precondition for the formation of diverse Bio-tops suitable for the environments of specific areas. Concrete researches on rooftop greening techniques will contribute to the improvement of urban ecosystem by developing more convenient and easily applicable techniques during the time of actual construction.